The present invention relates generally to the field of temperature measurement, and, in its most preferred embodiments, to the temperature measurement of liquid in a container.
Thermometers have been used to measure a variety of liquids in containers. One type of liquid currently being subjected to frequent scrutiny is urine. Studies have shown that the temperature of freshly voided urine can provide a good, less intrusive indication of core body temperature, thus providing for the detection of body temperature changes due to such causes as fever or ovulation. Furthermore, because of an increase in public awareness of drug abuse among people in many different areas of society, many organizations have initiated drug testing programs which analyze urine specimens. To help ensure the genuineness of a urine specimen, a thermometer is routinely used to verify that the temperature of the urine specimen approximates normal body temperature. The processes and devices heretofore used to determine urine specimen temperatures all suffer from a variety of potential problems.
U.S. Pat. No. 4,832,046, reissued as Re. No. 33,686 to James M. Parrish, discloses a method and an apparatus for collecting and detecting spurious urine samples. The Parrish patent discloses, as one embodiment, a single use urine collection container having an irreversible temperature sensitive member adhesively connected to the exterior of the collection container at a height below the level of the urine sample. The exterior temperature sensitive member is not necessarily acceptable in all testing situations. For example, some urine collection containers are constructed of plastic, a material normally having relatively low conductivity. One apparent consequence of poor conductivity is that the temperature sensitive member needs to be placed below the level of urine sample to ensure proper heat conduction through the collection container to the temperature sensitive member to obtain a proper temperature reading. Peculiar positioning problems may arise when only a small amount of urine is collected, assuming the collection container will accurately conduct the heat of a small amount of urine. Furthermore, the low conductivity increases the need for a very firm and thorough contact between the temperature sensitive member and the collection container, thus magnifying the consequences of improper affixation. Moreover, the collection container material may also introduce an unacceptable time delay in the heat transfer from the urine to the temperature sensitive member.
Furthermore, the method and apparatus disclosed by the Parrish patent do not appear to foster equipment reuse. Obviously it would be difficult to reuse the irreversible temperature sensitive member. It would also be difficult to reuse the temperature sensitive member on another collection container even if it were not irreversible because an adhesive connects the temperature sensitize member to the collection container. Successive removal and reapplication of the temperature sensitive member is likely to degrade the adhesive and the thermal contact between the temperature sensitive member and the collection container. Such degradation is likely to result in spurious temperature indications. Thermal contact is also likely to be degraded if additional adhesive is successively applied and allowed to build up between the temperature sensitive member and the collection container.
In conclusion, with respect to the method and apparatus disclosed in the Parrish patent, adhesively attaching a temperature sensitive member to the exterior of a collection container having relatively low conductivity presents many potential problems.
There is, therefore, a need in the industry for a method and apparatus which solves these and other related, and unrelated, problems.